Bloomington, MN Noise Ordinances: Decibel Limits (2026)

Section 10.29.02 of the Bloomington City Code is the numeric backbone of the Noise Code. It sets limiting levels of sound for receivers grouped by land activity into Noise Area Classifications, and the standards in subpart (a) apply to all sources.

The table has four columns in dBA: Daytime L50, Daytime L10, Nighttime L50 and Nighttime L10. L50 is the level exceeded 50% of the time and L10 the level exceeded 10% of the time for a one hour survey, measured by the test procedures in Minnesota Rules parts 7030.0060 and 7030.0070. Classification 1 reads 60, 65, 50, 55. Classification 2 reads 65, 70, 65, 70. Classification 3 reads 75, 80, 75, 80.

Classification 1 covers household units, hotels, motels and other overnight lodging, mobile home parks, medical and health services, educational services and religious activities. Classification 2 covers retail trade including restaurants and bars, business and professional services, repair services, automobile parking, public assembly and parks. Classification 3 covers manufacturing, highway and street right-of-way, utilities, and all other activities not otherwise listed. A Classification 4 list for undeveloped land, water areas and land under construction is printed, but the standards table has rows only for Classifications 1 through 3.

Under subpart (c), sound is measured at or within the applicable classification at the point of human activity nearest the noise source, and all measurements are made outdoors.

Subpart (d) lets a classification change. Classification 1 land uses the daytime standards at night when the use includes no overnight lodging. A Classification 1 building is held to Classification 2 standards if its exterior to interior attenuation is at least 30 dBA, it has year-round climate control and it has no areas intended for outdoor activities. Classification 3 standards apply to a Classification 1 building at attenuation of at least 40 dBA on the same conditions, and to a Classification 2 building at at least 30 dBA.

The section notes that these standards do not by themselves identify limits for impulsive noise. Section 10.29.01 adopts Minnesota Rules parts 7030.0010 through 7030.0080 by reference for standards and testing procedures. Under § 10.29.04 a city official can require a noise impact statement, and under § 10.29.05 new exterior air conditioning plants need city official approval and noise mitigation if they exceed § 10.29.02.